hey everyone, just wanted to see if i could get some feedback from everyone im working on my friends 99 7.3 dually and its having an intermittent no start issue. the truck cranks and the oil pressure will build but it will not fire and there is no WTS light if you cycle the key a few times then the WTS light will usually come on and it will fire after that but like i said its intermittent. the truck does have a 6 position ts chip and i have already removed the PCM connector and cleaned it with QD electronics parts cleaner thinking that there was a bad connection at the pcm (not tight, dirty) any help would be greatly appreciated thank all of you in advanced

 

now im no expert by any means, but I have been doing alot of looking as i recently had a no start issue and my buddy currently has a no start issue. with the mention of the wts light sometimes not coming on, I remember that being a main question when diagnosing along with "does the tach move while cranking" the wts light is linked with the pcm i believe, and the tach is the cps. there could be a wire rubbing somewhere, I will quote a previous thread maybe to help. It sounds electrical to me.

quote - "Have you checked the under the valve cover harness connections? They're known for melting and causing issues. I actually had one do the same thing when driving down the road, well down the interstate actually after it'd already been driven 1500miles on that trip. It wouldn't start, but occationally after it'd sit for several hours, it's start and run for a few seconds then die.

Turns out the UVCH connections were toast and there was no signal getting to the injectors, shutting them down. Had to replace all the wiring, engine harness included cause it was that bad."


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quote -"Sorry I dont know the fuse number, but one of the 30 amps fuses for the fuel bowl heater will blow when the heater shorts out and cause a no start with no wait to start light. If you have a blown fuse, unplug the heater at the fuel bowl and replace the fuse. "

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quote - "Check your fuses, sounds like the fuel bowl heater shorted, taking out the fuse, which also powers the PCM. I cant recall what the fuse number is, but its under the hood by the air filter box. If that fuse is blown, before you replace it, reach under the fuel bowl and unplug the fuel bowl heater.

Its not the CPS if you have no WTS light.

the fuse could be under ur dash too, my cousin kept blowing the fuse under the dash when his fuel bowl heater shorted out

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fuel bowl heater fuse inside cab is a 30 amp fuse in #30 spot "

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quote - "Originally Posted by wilke12V I had a similar issue just a few weeks ago that ended up being the connection between the battery posts and the cable terminals. Cleaned up both with a wire brush and all was OK. Worth a shot before you go down that rabbit hole. DAMHIK

 

You should see if the truck has any codes. I'm guessing you might have an IDM failure code. It could be the chip or IDM. Do you have his issue without using the chip?

 

the truck does have the same issue with the chip out but a local guy yes he is younger but hes pretty damn knowledgeable on power strokes says that when you take the chip out that it leaves almost a "ghost" tune on it like it is still on there the chip my friend has does not have a stock setting i dont know the validity of this theory of his but it would kinda make some sense